Combination tandem concrete-mixing machine



M ch 1 1927.

E. H. M MlLLAN COMBINATION TANDEM CONCRETE MIXING MACHINE Filed July 13, 1926 3 sheet Jwomtw Z/Z/Yflillan March 1 1927. 1,619,145

E. H. MCMILLAN COMBINATION TANDEM CONCRETE MIXING MACHINE Filed July 13, 1926 3 Sheets-Sheet 2 Jwwmtw E H/Y-flillan Guam 1,619,145 March 1 1927- McMlL LAN COMBINATION TANDEM CONCRETE MIXING MACHINE Filed y 13. 1926 3 Sheets-Sheet 5 terial and so that there is at Patented Mar. 1, 1927.

UNITED STATES EDWARD H. MOMILLAN, OI OAKLAND, CALIFORNIA.

COMBINATION TANDEM CONCRETE-MIXING MACHINE.

Application filed July 18, 1828. Serial No. 122,257,.

This invention relates to concrete mixers and particularly to mixers having a rotatable drum into which the materials are placed and tumbled about until thoroughly mixed.

The general object of the present invention is to provide a concrete mixing machine which is particularly adapted for mixin concrete for pavements or highways and which is so constructed that it will mix thoroughly and cut down the time of delivering the product.

A further object is to provide a construction of this character which will thoroughly mix the sand, concrete, and aggregate for the required length of time and yet which will cut down the time of delivering the product, my improved concrete mixer using two drums and the mixture being in each drum one-half the required time.

Another object is to provide a construction of this kind having two drums in tandem, the raw or unmixed material being placed in the first drum and revolved therein for one-half minute, then transferred to the second drum and revolved therein for one-half minute so that while the material is being mixed in the second drum, the first drum is receiving a new batch of raw maall times a batch of raw material in one or the other of the drums and almost a continuous deliverance of concrete from the mixing machine to the work, thus eliminating loss of time in waiting for the material to be thoroughly mixed, and'eliminating any necessity of cutting down the mixing time to increase the quantity of yardage at the expense 0 quality.

A further object is to provide a construction of this kind wherein the drums are mounted upon a tractor frame (preferably of the caterpillar type) so that the concrete mixer may be shifted from time to time to suit the progress of work.

A still further object is to provide a concrete mixer with a drum mounted upon three rollers so as to secure a three point roller contact and a further object is to provide the rollers and the track with beveled faces complementary to each other which will take up side thrust when traveling up or down grades or on inclines and which willfurther enable the drums to have more adhesion and secure a constant rolling motion without slippage.

f plates 16. The lower Other objects will appear in the course of the following description.

My invention is illustrated in the accompanymg drawings wherein Figure 1 is a side elevation of a mixing machine constructed in accordance with my invention;

Fig. 2 is a vertical longitudinal section thereof;

3 is a front elevation thereof; F1g. 4 1s a fragmentary section on the l1ne 4-4 of Figure 1;

Fig. 5 is a detailed elevation of the means for driving the rearward shaft sections, theclutch being in section.

Referring to these drawings it will be seen that generally speaking, I have 'provided a tractor supported frame and that mounted upon this frame are two drums ar ranged in tandem relation, the first drum of the series receiving the raw materials from a skip or other feeding means, and dischar ing into the second drum which, in turn, ischarges into any suitable clhut'e, skip, bucket, hoist, or other delivering means. It will be seen that the base frame of the machine includes longitudinally extending beams 10, upon which are mounted a plurality of supporting wheels 11 and that these beams 10 also support at their ends, the transverse shafts 12 and 13, the shaft 13 being a two-part shaft, as will be later explained. The shaft 13 supports at its ends the bull wheels 14 and the shaft 12 supports the bull wheels 15. Over these wheels pass the endless chain of grouser flight of the track or chain passes beneath the wheels 11 and over wheels 11.

The shaft 13 is referabl formed in two sections, each of t ese sha t sections being independently driven, as will be later explained. The beams 10 support the transverse beams 17 and mounted upon these transverse beams are the longitudinal beams 18 which support, by any suitable braces, the relatively long transverse beams 19, upon which the front drum 20 is mounted. The drum may be constructed in any suitable manner and has surrounding it the circumferentiall extending sectional track 21. This trac has outwardly inclined faces 22.

Mounted in bearings upon the beams 19 are two rollers 23 which engage this track, these rollers having beveled end faces 24 which eng the beveled faces 22. For the tion it will receive material from within purpose of olding the drum in place upon the drum and d iscba this material the rollers 23 I provide a top roller 25, downwardly and rearwar y to the second which is formed in the same manner as the drum. The drum 20 is also provided with rollers 23 and also has beveled end faces to a plurality of transversely extending pick- 70 engage the beveled walls of the track 21. up buckets or blades 49 which may be of This up r roller 25 is mounted upon transany suitable character and ma be sh htly verse c annel irons or beams 26. These inclined central! or towards e disc arge beams on one side are pivotally connected opening or, on the other hand, ma extend to a downwardly extending hanger 27 which horizontally across the drum 20. e dis- 7:; is pivotally mounted between the longitudicharge mouth 47, as shown in Figure 2, has na ly extending beams 01' channel irons 28, its annular wall extending inward and centhese beams being in turn mounted upon trally beyond the side wall of the drum in transverse beams 29, in turn carried b? upboth directions so asto prevent material ri 'hts 30 extendin down to the base rame bein mixed within the drum from being 1 the machine. e outer ends of the pair disc is! ed through the discharge opening of beams 26 are provided with a transversely exiaipt y the use of the chute 48. extending yoke 31 and extending upward ounted upon the supporting frame bethrough the yoke 1s a pm or rod 32 which lund the drum 20 is the drum 50 which is is pivotally enga d with the channel irons constructed in exactly the same manner as 28 on that side 0 the machine by means of the drum 20 and is sup orted in the same a detachable pin 33. Called 5 rings 34 are manner but is of slighti; different dimendisposed around this pin or re 32 and bear alone, the drum bein preferably narrower against the yoke 31 and thus act to hold the than the drum 20. T is drum 50 is also probeams 26 in a middle position and yielding vidcd with a receiving chute 45 of the same against either upward or downward movecharacter as the receiving chute 45, and ment. A nut 35 engages the upper end of with a discharge mouth 47, and with a disthe screw pin 32 an y adjust this nut charge gate or chute 48' mounted in the the tension of the springs 34 may adjustsame manner as the chute 48 but discharged. Thus, it will be seen that the upper ing into a receiving chute, trough, or other roller 25 is yieldingly forced downward equivalent element 51. The drum 50 is also against the track, and that the two lower provided with transversely extending blades rollers 23 and the up r roller 25 are dis- 49 and operates in precisely the same manposed in approximate y triangular relation ner as the drum heretofore described. This and have three pointsof contact with the drum is also supported by a three point drum track. roller contact consisting of the rollers 23' The drum is rotated by means of the shaft and the single roller 25 at the to of the 36 carrying two gear wheels 37 which endrum. These rollers engage with t e track gage with annular racks 38 or gear teeth in 21', of the same character as heretofore deturn carried upon the drum. he shaft 36 scribed, having beveled faced side walls with 1 is driven by means of a sprocket wheel 39 which the beveled edges of the rollers endriven by a s rocket chain 40 extending over gage. a sprocket wheel 41 mounted upon the shaft It will be noted that the gates or chutes 42 of the motor or engine 43, which in turn 48 and 48* are mounted upon transverse is mounted upon asuitable su porting structrunnions 52 mounted in brackets53 and ture extending upwardly mm the base 53, the brackets 53 being operatively conframe and supporting the engine to one side nected to uprights 30 and the brackets 53 but in advance of the front drum. being connected to upwardly and rearward- The drum 20 is formed with a central re- 1 extending supporting beams 54. The rear ceivin olpening 44 having therein one end (ii-um is also driven by means of pinions of a isc arge chute 45 and adapted to re- 37' carried by a shaft 36, which in turn oeive materia from a skip46 of any suitable carries a sprocket wheel 39 driven by a character and which forms no (partof my sprocket chain from a s rocket wheel on invention. This ski is designs to receive shaft 42. Obviously, I (1% not wish to be the raw material 0 the concrete when the limited to this manner of driving the drums skip is lowered and when hoisted by means as the caring for this purpose might be not necessa to state, the raw material is change in many ways without departing discharged through the chute 45 into the infrom the spirit of the invention. The gear terior of the drum. The opposite end of wheels 37", of course, engage the annular the drum is formed with a discharge mouth gear rin 38. Manually operable means is 47 and pivotally mounted within the disprovide engageable with the shafts or trunchargle mouth is a transferring chute or gate nions 52 whereby the ates 48 and 48 may 48 w ich is adapted to swing from the full be turned from a disc ar e position to the line position in Flgure 2 to the dotted line position shown in dotte lines, or means position. When it is in its full line posimay be provided whereby these gates are automatically turned to their discharge positions dperiodically. Water tanks are mounte upon the supportin frame of the mechanism and are provid with suitable pipes discharging water into the mixing drums in a manner which will be obvious.

For the purpose of driving the tractor I provide an engine 56 supported upon the rame of the machine opposite to the engine 43, the shaft of which carries upon it the sprocket wheel 57. This is engaged with the sprocket wheel 58 mounted upon a longitudinal shaft 59 which carries upon it a beveled ear wheel 60.

Slidab y. mounted u on the transverse shaft 61 are the two eveled gear wheels 62 and 63, either of which maybe shifted by suitable shipper levers into engagement with the beveled gear wheel 60. Thus, the shaft 61 may be driven in opposite directions.' The shaft 61 carries upon it the sprocket wheels 64. Mounted in suitable bearings upon the frame of the machine are the two shaft sections 65 and 66 which carry the bull wheels 14. Each shaft section carries upon it the sprocket wheel 67 driven from one of the s rocket wheels 64 by means of a sprocket c ain. These two shaft sections 65 and 66 may be independently operated if desired or both operated together. To this end I have shown a male clutch member 68 mounted upon the shaft section 65, which clutch member is recessed at its center to receive the extremity of the shaft section 66. Ke ed upon this shaft section 66 is the shifta 1e female clutch member 69 ,shifted into or out of engagement with the clutch member 68 by any suitable shifting means. Also keyed upon the shaft section 66 is a circular supporting block 70 which is concentric to the shaft and fits within a recess in the clutch member 68 and is held in place b a collar 71 disposed within the recess 0 the clutch member-68. By this means one of these shafts may turn independently of the other shaft if such a condition be desired and if it be required that both sections shall operate together as a unit, the two clutch members are engaged with each other. be used to hoist the skip 46 or operate any other desirable feed means. Obviously, by driving one of the shaft sections 65 or 66 and letting the other run idle, the machine may be steered and shifted laterally. Thus, not only may this machine follow in its work but it may travel from one jo to another under its own power.

While I have illustrated a crawler or caterpillar tractor for supporting and causing the movementcf the mlxing machine, I do not wish to be limited to this as ordinary motor truck or tractor mechanism might be used in place of the caterpillar tractor.

It wil be seen that with this construc- The engine 56 may also tion, concrete instead of being mixed in a single drum for a specified time of, for instance, one minute, is mixed in two drums for the same length of time that is, a half minute in each drum which secures not only a more thorou h mixture of the material by reason of the transfer of the material from one drum to the other but eliminates the time lost where a single drum is used, in receiving material and in discharging it as in my construction the first drum may receive 1ts raw material while the other drum is discharging it. Thus, the raw or unmixed material is placed in the first or front drum and is revolved therein for a half minute, then it is transferred to the second drum and revolved within this drum a half minute at about the same time the first or front drum has received another batch of raw material and after the first batch at the commencement of the work has been delivered to the second or rear drum from the first drum, there is almost continually a batch in each drum and at about the same time there is almost a continuous stream of concrete being delivered from the mixing machine to the work. Thus there is no loss of time due to waiting for the material to be thoroughly mixed and there is no necessity of cutting down the time of mixing in order to increase the quantity or yardage at the expense of quality. A concrete mixer constructed in accordance with my invention will turn out more cubic yards of thorou hly mixed concrete per hour than any ot er concrete mixing machine known to me and the mixed concrete so turned out will be of better uality than other concrete mixing machines nown to me.

p The roller support which I have provided for the drums secures greater adhesion between the drums and the driving mechanism, thus eliminating slippage and the three point roller contact steadies the frame at all times. The beveled faces of the rollers operating against the beveled track tend to take side thrust when the machine is operating on an inclined plane or traveling up or down grades.

I claim 1. A separate and independent mixing machine comprising two mixing drums mounted in tandem and each having a centrally disposed receiving opening and a centrally disposed discharge opening in its opposite ends, a gate having the form of a chute pivotally supported in connection with the discharge opening of the first drum and adapted to be shifted into a downward ly inclined position to receive material from the first drum and discharge it into the second, and a gate pivotally mounted in connection with the discharge opening of the second drum and shiftable from an inoperative position to a downwardly and outwardill) lUil

iii

-. from, each of said gates ly inclined position each of said gates having rtions extending into its corresponding rum, each drum having separate driving means.

2. A mixing machine of the character described comprising a supporting frame having wheels, means for driving the frame forward or backward, a pair of separate and inde ndent mixing drums mounted upon the me, the forward mixing drum being disposed with its axis higher than the rear mixing drum, each of said mixing drums having a centrally disposed receiving opening and a centrally disposed discharge opening, a chute-like gate pivotally mounted inconnection with the discharge opening of the first named drum and when shifted into one position discharging material from the first named to the second named drum, a pivoted chute-like discharge gate mounted in connection with the discharge 0 nin of the second named drum and a apte to be turned into a downwardl inclined position to dischar material t ereaving a portion extending into the corresponding drum and each of said drums having transversel extending baflies to cause the elevation 0 material as the drum is rotated and separate power driven means for operating each drum.

3. A mixing machine of the character described comprising a wheeled supporting frame, means for propelling the frame either forward or rearward, a lurality of separate and independent rotata le drums mounted upon the frame and one discharging into the other, and independent power operated means for operating said drums.

4. In a mixing machine of the character described, a supporting frame, a havmg a plurahty of gear' rings, a circular track mounted upon each drum, and rollers mounted upon the frame and coasting with the circular track, said rollers being .ar-

ranged to engage the drum at three as arated points, one of said rollers being yie dmgly urged toward the drum.

5. In a mixing machine of the character described, a supporting frame, a drum hav- 6. A mixing machine comprising a supporting frame, a rotatable drum thereon, means for supporting the drum including a circular track on the frame and three rollers engaging said track, two of said rollers being mounted upon the supporting frame beneath the frame, a transversely extending beam pivotally mounted upon the supporting frame and extending above the frame, and carrying the uppermost roller, a vertical bolt operatively engaging the frame on the other side thereof from said pivotal support for the beam, and upper and lower springs carried by said bolt and operatively engagmg the free end of said transverse beam and yieldingly holdi beam in a norms. position the track. p

In testimony whereof I hereunto aiiix my signature.

EDWARD H. MOMILLAN.

aring against to engage the drum at three sepangnthe transverse (ill r. from, each of "said gates 1y inclined position each of said gates having rtions exten 'ng into its corresponding rum, each drum having separate driving means.

2. A mixing machine of the character described comprising a supporting frame having wheels, means for driving the frame forward or backward, a pair of separate and independent mixing drums mounted upon the ame, the forward mixing drum being disposed with its axis higher than the rear mixing drum, each of said mixing drums having a centrally disposed receiving opening and a centrally disposed discharge opening, a chute-like gate pivotally mounted in connection with the discharge opening of the first named drum and when shifted into one position discharging material from the first named to the second named drum, a pivoted chute-like discharge gate mounted in connection with the discharge 0 nin of the second named drum and a apte to be turned into a downwardly inclined position to discharge material thereiaving a portion extending into the corresponding drum and each of said drums having transverse] extending bailles to cause the elevation 0 material as the drum is rotated and separate power driven means for operating each drum.

3. A mixing machine of the character described comprising a wheeled supporting frame, means for propelling the frame either forward or rearward, a lurality of separate and independent rotata 1e drums mounted upon the frame and one discharging into the other, and independent power operated means for operating said drums.

4. In a mixing machine of the character CERTIFICATE OF Pgtent No. l, 619, 145.

described, a supporting frame, a drum havmg a plurality of gear rings, a circular track mounted upon each drum, and rollers mounted upon the frame and coasting with the circular track, said rollers being .arranged to engage the drum at three se arated points, one of said rollers being yiel mgly urged toward the drum.

5 In a mixing machine of the character described, a supporting frame, a drum havmg a plurality of gear rings, a circular track mounted upon each drum, and rollers mounted upon the frame and enacting with the circular track, said rollers being arranged to engage the drum at three separated points, one of said rollers being yieldingly held in contact with the track and against inward or outward movement from a normal position.

6. A mixing machine comprising a sup porting frame, a rotatable drum thereon, means for supporting the drum including a circular track on the frame and three rollers engaging said track, two of said rollers being mounted upon the supporting frame beneath the frame, a transversely extending beam pivotally mounted upon the supporting frame and extending above the frame,

and carrying the uppermost roller, a vertical bolt operatively engaging the frame on the other side thereof from said pivotal support for the beam, and upper and lower springs carried by said bolt and operatively engaging the free end of said transverse beam and yieldin 1y holdin the transverse beam in a norma position %iearing against the track. 7

In testimony whereof I hereunto afiix my signature.

EDWARD H. MOMILLAN.

CORRECTION.

Granted March 1, 1927, to

cnwaan a. McMlLLAN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Page 3, line 116, claim 1, strike out the words "separate and independent" and insert the same after the word "two" in line 117; and that the said Letters Patent should be read with this correction therein that the same may the Patent Office.

conform to the record of the case in Signed and sealed this 9th day of December, A. D. 1930.

(Seal) M. J. Moore, Acting Commissioner of Patents.

CERTIFICATE OF CORRECTION.

Pgtent No. l,6l9,l45. Granted March 1, 1927, to

EDWARD H. McMILLAN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 3, line 116, claim 1, strike out the words "separate and independent" and insert the same after the word "two" in line 117; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 9th day of December. A. D. 1930.

M. J. Moore. (Seal) Acting Commissioner of Patents. 

